Automatic fluid sample apparatus

ABSTRACT

An automatic fluid sample apparatus for the chemical analysis of fluids is described. In the apparatus, a plurality of samples are substantially simultaneously precisely measured out and diluted or mixed with the proper quantity of diluent and/or reagent. A series of tubing valves, preferably of the T-type, in one position permit sample containers having the desired sample volume to be filled with samples of fluid to be analyzed from a fluid source through the action of a vacuum pump. The valves are then placed in a second position whereby the samples flow from the sample containers to recipient containers and respective proper quantities of diluent or reagent are caused to flow through the valves and the sample containers into the recipient containers.

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[45] Patented Sept. 21,1971 [7 ll Aaaigncc International Business Machines Primary Examiner-William R. Cline (.orporatlon Allurneys-Hanifin and Jancin and Isidore Match Armonk, N.Y. I Continuatlomin-part of application Ser. No. 653,141, July 13 19 7 now abandoned ABSTRACT: An automatic fluid sample apparatus for the chemical analysis of fluids is described. In the apparatus, a plurality of samples are substantially simultaneously precisely measured out and diluted or mixed with the proper quantity of diluent and/or reagent. A series of tubing valves, preferably of the T-t e, in one osition ermit sam le containers having [54] AUT9MATIC FI,UID SAMPLE APPARATUS the desii' d sample olume tcfbe filled w ith samples of fluid to 6 Clalms 2 Drawing be analyzed from a fluid source through the action of a [52] US. vacuum pump. The valves are then placed in a second position whereby the samples flow from the sample containers to recipient containers and respective proper quantities of diluent or reagent are caused to flow through the valves and the sample containers into the recipient containers.

[51] Int. G01n 33/16 [50] Field of 137/565,

PATENTEUSEPZHBYI 3,507,092

SHEEIIUFZ I INVENTORS GORDON W. NEFF JOHN E. TOMKO ATTORNEY PATENTED SEP21 IQYI SHEET 2 [IF 2 T0 SAMPLE EONTMNERS 24, 26

AND 28 FIG.2

AUTOMATIC FLUID SAMPLE APPARATUS This application is a continuation-in-part application of copending patent application, Ser. No. 653,141, filed July 13, 1967, now abandoned.

BACKGROUND OF THE INVENTION This invention relates to wet chemical analysis of fluids. More particularly, it relates to an improved apparatus for automatically providing properly diluted samples of body fluids to be analyzed.

In the chemical analyses of body fluids, most analytical procedures entail the measuring out of a given volume of a sample of a fluid to be analyzed for the mixing thereof with a prescribed volume of a chosen diluent and/or reagent. Generally, in these procedures, the ratio of diluent volume to sample volume is chosen to be relatively high and the utilization of sample volumes in the microliter range are common.

There are many known apparatus and techniques for the carrying out of these analyses and for the providing of a small volume sample and the mixing of it with a diluent and/or reagent. A well-known technique, for example, for achieving the dilution of a microliter sample is to draw the sample into a small tube with a syringe or piston while simultaneously filling another piston with the required volume of diluent and/or reagent. Through appropriate valving, the piston containing the diluent and/or reagent is emptied out through the sample containing tube into a recipient container which thereby contains the properly diluted sample. This technique requires that the sample syringe be immersed into the sample source for the drawing of the sample thereinto and then the withdrawing of the sample tube from the source and the moving of it into position over the recipient container. A careful wiping of the sample tube once it has had the sample drawn thereinto is necessary since a drop of sample at the syringe end or a film of sample on the outer surface of the syringe in the case of a redilution can be equal to or even exceed the amount of the actual sample drawn into the sample syringe.

To achieve multiple sampling, it is necessary to accomplish the sample drawing and its dilution by either a serial or parallel method. In the serial method, the sample syringe has to be reciprocally moved between a sample source and a recipient container and has to be wiped during its movement from the source to the container. In the parallel method wherein several sample syringes and dilution pistons have to be employed, all of the sample syringes have to be moved between the sample source and the recipient containers.

The above set forth techniques have been found to be adequate for manual operation. However, in automatic arrangements, they have been found to be not practicable since the reciprocal movements of the sample tubes and their wiping or cleaning becomes complicated and introduce complex and costly factors into automatic methods.

Accordingly, it is an important object of this invention to provide an apparatus for automatically providing a plurality of precise samples from a sample source wherein mechanical motions and other operations are substantially minimized.

It is another object to provide an apparatus in accordance with the preceding object which is simple in construction and relatively inexpensive.

SUMMARY OF THE INVENTION In accordance with the invention, there is provided an apparatus for automatically providing a plurality of samples of a chosen volume of a first fluid to be analyzed, diluted with a prescribed volume of a second fluid selected from the group consisting of a diluent and a reagent. The apparatus comprises a source of the first fluid, a source of the second fluid, a plurality of first containers for receiving the respective samples of the chosen volume of the first fluid thereinto and a plurality of second containers for receiving the respective samples of the chosen volumes of the first fluid diluted with the prescribed volumes of the second fluid thereinto. There are further ineluded valve means associated with the first and second fluid sources and the first and second containers, the valve means being adapted in a first position to permit the first fluid to be drawn into the first containers from the first fluid source and, in a second position, to permit the first fluid to flow from the first containers into the second containers and to permit the second fluid to flow from the second fluid source into the second containers through the first containers. There are also provided first pump means associated with the first fluid source for drawing the plurality of samples of the aforesaid chosen volume into the first containers and second pump means for pumping the plurality of second fluid volume into the second containers through the first containers.

The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of a preferred embodiment of the invention, as illustrated in the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 is a schematic depiction of an illustrative embodiment of an apparatus constructed in accordance with the principles of the invention; and.

FIG. 2 is a schematic drawing of an arrangement suitable for use as a reagent or diluent metering means in the system shown in FIG. 1.

DESCRIPTION OF A PREFERRED EMBODIMENT Reference is now made to FIG. 1 wherein there is schematically depicted an illustrative embodiment constructed in accordance with the principle of the invention.

In this embodiment, the structure designated with the numeral 10 represents a vessel for containing the fluid which is to be analyzed and from which samples are to be taken for such analysisQThe structures designated with the numerals 12, 14 and 16 respectively represent recipient containers, i.e., those containers which are to contain the samples precisely diluted with the proper amount of diluent or mixed with the correct amount of reagent. The structures designated with the numerals 18, 20 and 22 represent vessels which contain the diluents or reagents. Containers 18, 20 and 22 can each contain different diluents or reagents and suitable means (not shown) such as stopcocks and the like can be inserted into the delivery lines from containers 18, 20 and 22 to provide flow as desired. The structures designed with the numerals 24, 26 and 28 represent sample containers and are suitably constructed to have capacities respectively precisely equal to the desired volumes of the samples from source 10. The structures designated with the numerals 19, 21 and 23 respectively are suitable pumps for propelling fluid from containers 18, 20 and 22 in prescribed volumes.

The structures designated with the numerals 30, 32, 34, 36, 38 and 40 respectively represent simultaneously operated tubing valves which are capable of assuming two positions, vis, the S and D positions, the S position being the position in which diluent or reagent from reagent containers 18, 20 and 22 is permitted to flow through the valves, the D position being the position in which samples drawn from the fluid in vessel 10 is permitted to flow through the valves into sample containers 24-28. In FIG. 1, the valves are shown in the D position. Valves 3M0 are preferably chosen to be tubing valves of the T-type. The various connecting lines in FIG. I represent delivery lines. A stage 42, legended vacuum pump, provides a vacuum for effecting suction to draw samples from source 10 into sample containers 24, 26 and 28.

In considering the operation of the apparatus shown in FIG. 1, valves 3040 are first placed in the D position and suction is applied to fluid container 10 from pump 42. Consequently, sample fluid is drawn up from container 10 and flows through valve 40, sample container 28, valve 32, sample container 26, valve 38, valve 36, container 24 and valve 30 until sample containers 24, 26 and 28 are filled. At this juncture, valves 30,

32, 34, 36, 38 and 40 are switched to the S position and pumps 19, 21 and 23 are actuated to cause fluid to flow from containers 18, and 22 respectively as desired. At this time, the chosen volume of sample flows out of container 24 through valve 36 into recipient container 12 and a prescribed volume of fluid as determined by pump 19 flows through valve 30, container 24 and valve 36 into container 12; the chosen volume of sample flows out of container 26 through valve 38 into container 14 and a prescribed volume of fluid as determined by pump 21 flows from source 20 through valve 32, container 26 and valve 38 into container 14; and, the chosen volume of sample flows out of container 28 through valve 40 into container 16 and a prescribed volume of fluid as determined by pump 23, flows from source 22 through valve 34, container 28 and valve 40 into container 16. With this arrangement, there are respectively produced precisely diluted or reagent mixed samples in recipient containers 12, 14 and 16.

The advantages obtained from the apparatus depicted in the drawings as compared to known apparatus for the same purpose are many. Thus:

I. the needle in the sample container is dipped into the fluid to be analyzed only once to provide multiple samples. When it is necessary to wash the sample needle to eliminate the possibility of contamination when the fluid is changed or the needle is immersed in a different fluid and contained in a different container, the sample needle need only be moved to a washing station and back to the fluid container.

2. The desired volume of the sample is determined by providing a selected capacity for sample containers 24, 26 and 28.

3. A plurality of samples are simultaneously measured out from a single fluid container.

4. The carryover from one sample in a container 24-28 to another is substantially negligible nor is any problem presented with the last drop.

5. The dispensing of the sample and tne diluent or reagent is effected through fixed lines.

6. Because all of T-valves 3040 are simultaneously operated, only a single power source such as a motor and a single electrical control are necessary to operate all of the valves. The motor or power source and the control are not shown in the drawings. However, since such sources and controls are well known, their depiction is deemed unnecessary.

Reference is now made to FIG. 2 wherein there is shown an arrangement suitable for use as a reagent or diluent metering means in the system shown in FIG. 1. In this arrangement, the diluent is contained in a stoppered container 44. The application of pressure from pump such as pump 42 (FIG. 1) through tube 46 causes diluent or reagent in container 44 to flow through tube 48. When a flexible tubing valve 50, similar to valves -40, is in the D position, diluent or reagent is permitted to flow from tube 48 through valve 50 into a precision syringe 52. It is to be noted that valve 50 is depicted in reference to numeral 14 FIG. 2. However, its structure and operation is the same as any of valves 3040. The pressure applied to container 44 from pump 42 causes the diluent or reagent to fill syringe 52 and to force a syringe plunger 54 to travel the distance required to cause it to abut against a syringe stop 56, the pressure of the liquid causing the extension of plunger springs 58 and 60. Now, when valve 50 is switched to the S position, plunger 54 is caused to resile by the tensioning action of springs 58 and 70 to thereby expel the contents of syringe 52 into the line to flow through sample containers 24, 26 and 28.

The arrangement shown in FIG. 2 is advantageously employed since it is readily adapted into a system, such as shown in FIG. 1, using only the system single power source and timor reagent is provided when the syringe is filled therewith.

It 18 to be noted that, within the contemplation of the invention, many other system configurations are possible. Thus, a peristaltic pump having a plurality of pump lines, can be employed to both effect the drawing of samples and the loading of the precision syringe simultaneously. A motor driven syringe pump could be used for each diluent or reagent container.

In situations where the volumes which are employed are relatively large and valve carryover becomes insignificant, a sample check valve may be employed instead of a T-valve when position pressure is applied to the syringe plunger.

While the invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes in form and details may be made therein without departing from the spirit and scope of the invention.

What is claimed is:

1. An apparatus for automatically providing a plurality of samples of a chosen volume of a first fluid to be analyzed diluted with a prescribed volume of a second fluid selected from the group consisting of a diluent and a reagent comprising:

a source of said first fluid;

a source of said second fluid;

a plurality of first containers for receiving said samples of said chosen volume of said first fluid thereinto;

a plurality of second containers for receiving said samples of said chosen volumes of said first fluid diluted with said prescribed volumes of said second fluid thereinto;

respective valve means associated with said first and second fluid sources, and said first and second containers, said valve means being adapted in a first position to permit said first fluid to be drawn into said first containers and in a second position to flow from said first containers into said second containers and to permit said second fluid to flow from said second fluid source into said second containers through said first containers;

pump means associated with said first fluid source and said valve means for drawing said plurality of samples of said chosen volume into said first containers; and

means interconnecting said containers, said valves and said pump means for directing said first fluid from said first fluid source into said first containers when said valve means are in said first position and for directing said first fluid from said first containers into said second containers and for further directing said second fluid from said second fluid source through said first containers and into said second containers when said valve means are in said second position.

2. An apparatus as defined in claim 1 wherein said valve means are adapted to be simultaneously operated.

3. An apparatus as defined in claim 2 wherein said valve means are tubing valves of the T-type.

4. An apparatus as defined in claim 3 wherein there is further included precision syringe means disposed intermediate said second fluid source and said first containers, and a T-type tubing valve associated with said syringe means.

5. An apparatus as defined in claim 3 and further including pump means associated with said second fluid source.

6. An apparatus as defined in claim 1 wherein said first containers are chosen to have a capacity substantially equal to the desired volumes of said samples. 

2. An apparatus as defined in claim 1 wherein said valve means are adapted to be simultaneously operated.
 3. An apparatus as defined in claim 2 wherein said valve means are tubing valves of the T-type.
 4. An apparatus as defined in claim 3 wherein there is further included precision syringe means disposed intermediate said second fluid source and said first containers, and a T-type tubing valve associated with said syringe means.
 5. An apparatus as defined in claim 3 and further including pump means associated with said second fluid source.
 6. An apparatus as defined in claim 1 wherein said first containers are chosen to have a capacity substantially equal to the desired volumes of said samples. 